The present invention relates to the use of electromagnetic fields to affect the movement of insects such as German cockroaches and firebrats. More particularly, it relates to the use of electromagnetism to facilitate attracting/repelling, trapping and/or killing of such insects.
Traditionally there have been attempts to control insect infestation through sanitation procedures (e.g. the prompt removal of potential harborages and food sources such as garbage). However, even with the utmost vigilance this often is not completely effective. For example, even a completely sanitized apartment can become somewhat infested with insects if there are surrounding apartments in the same building, and those apartments and/or a common sanitary system, remain infested.
Particularly problematic insects to completely control are crawling insects such as cockroaches. These insects are adept at infiltrating into residences through sanitary systems and cracks.
Hence, insecticides and other insect control chemicals and/or biological agents have been used to try to further control such insects. See generally U.S. Pat. No. 5,030,660 (deterrent substances), U.S. Pat. No. 5,066,482 (reproductive inhibitors), U.S. Pat. No. 5,302,387 (toxins), and U.S. Pat. No. 5,057,316 (fungal agents). The disclosure of these patents, and of the following other publications referred to herein, are incorporated by reference as if fully set forth herein: U.S. Pat. Nos. 4,802,057, 4,870,779, 5,424,551, 5,572,825, 5,560,146, 5,896,696, 5,930,946 and 6,574,913.
There have also been attempts to rely on chemical or biological attractants to lure the insects to a trap or killing station. See generally U.S. Pat. Nos. 5,572,825 and 5,560,146. For example, pheromones have been used to attract cockroaches to a trap.
While chemical/biological approaches have considerable effectiveness in many cases, they do have some drawbacks. For example, insecticides often are not effective unless the insect directly contacts the insecticide. Further, the effectiveness of chemical or biological lures typically rapidly drops with distance from a baiting station or the like. Thus, multiple baiting stations may be required for adequate coverage of even relatively small residences or patio areas. Also, if the luring system requires an odorous volatile to be dispensed from a trap, consumers who find such odorants undesirable may not prefer that approach.
An alternative, very different, approach to insect control is to provide a large scale release of sterile insects. While this approach has been of some success on cargo ships and in certain agricultural and industrial settings, it is not desirable for application in residential settings. Homeowners are not typically willing to expose their families to a substantially increased infestation, notwithstanding the promise of future control of the insects.
There have also been attempts to attract certain insects, particularly flying insects, using visible lights of certain wavelengths. However, these light-based attractants typically are also visible to consumers, and/or have an undesirable sound associated with their generation or use, which has undesirable aesthetic effects.
In U.S. Pat. No. 6,574,913 there was a discussion of using sonic signals in combination with chemicals to improve attraction of certain insects. See also U.S. Pat. No. 5,424,551 regarding exposing varied animals to particular selected frequencies. Apart from audible sounds possibly annoying some consumers, certain sounds can spook other types of insects (and thus repel them).
There have also been teachings that use of pulsed electromagnetic fields act to repel certain insects and other pests. See generally U.S. Pat. No. 4,802,057 (rodents), U.S. Pat. No. 4,870,779 (rodents and insects), and U.S. Pat. No. 5,930,946 (cockroaches). See also U.S. Pat. No. 5,896,696. This would teach away from applying electromagnetic fields as an attractant, and in any event indicate that pulsing is important in causing repelling.
Hence, there is a need for improved, low cost, insect trapping and killing devices which are suited to use in a residential environment.